Apple iPhone XR schematic in PDF form, the second part or alternate copy judging by the suffix in the name, at 48.8 MB. Diagrams like this let a technician follow power rails from the PMIC, trace charging, display, camera and baseband lines, and identify which connector pins and components share a net when hunting a short. Use it together with an XR boardview to locate parts physically on the stacked logic board, and check that the page set matches the board variant you are repairing before trusting part designators.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @uzb4422. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.